So I visited a building (B occupancy office tower) that had a 4-5 story stair atrium with monumental stair and no smoke evac system.
The only thing it did have is glass draft curtains at each level.
How would this be possible?
Perhaps it was built decades ago?
Sorry, it was completed last year. It’s a class-A office building for a well known international company, designed by a top 20 architectural firm.
Does the curtain wall have operable vents on motors connected to the fire alarm?
Not that I could tell from inside or by looking at pictures of the roof. All sides of the clerestory looks like this…
Brian; Maybe they used the escalator provisions in section 712.1.3 in the 2015 IBC, also look specifically at 712.1.3.1 for the draft curtains. This section applies to B&M occupancies up to 4 stories.
I saw that. Interesting that escalator openings are treated differently than stairs in the code. In this case it is a stair, not escalator, and it is 5 connected stories in most of the locations.
Brian; The stories aside I have used this section for stairs before after convincing the BO that their is no real difference between a “stationary” stair and a “moving” stair.
I’m curious how the escalator (or stair) provisions would negate the need for smoke control for an atrium. Adding some draft curtains at the edges of the floor openings at an atrium doesn’t make it less of an atrium. It would still need to comply with Section 404 (and 909) … or is there something I’m missing?
I could see that perhaps the draft curtains help in the design of a smoke control system, but you would still need the system.